Montreal Doctors Cure Teen's Immune Disease With Gene Editing

A teenager with chronic granulomatous disease can finally live without fear after doctors at Montreal's CHU Sainte-Justine essentially cured his rare immune disorder using revolutionary gene therapy.

Last spring, Dr. Élie Haddad and his team achieved what many thought impossible. They corrected the genetic mutation causing the disease directly in the patient's stem cells using a technique called "prime editing."

One year later, the results speak for themselves. The 18-year-old from British Columbia shows no symptoms whatsoever, and about 75% of his previously diseased white blood cells have been permanently corrected.

"It's stable, it's exactly what we had at the beginning," Dr. Haddad said. "This stability strongly suggests that it will last forever."

The young man now lives a normal life, though he still travels from Vancouver to Montreal for regular checkups. Dr. Haddad monitors his progress closely, but admits there's an encouraging sign when patients grow weary of the visits.

"The best sign is when the patient gets tired of coming in," he explained. "If they feel like they're coming in for nothing, that means they're on the road to recovery."

The Ripple Effect

This breakthrough could transform treatment for countless genetic diseases. Prime editing goes beyond traditional gene therapy, which simply replaced defective genes with healthy ones.

This new technique can correct virtually any genetic mutation with precision. Dr. Haddad uses words like "revolution" and "magic wand" when describing its potential.

The treatment also proved safer than conventional approaches. Patients with chronic granulomatous disease typically need bone marrow transplants after brutal chemotherapy, with survival rates around 80 to 90%.

Prime editing uses gentler preparation and eliminates rejection risk since patients receive their own corrected cells back. The survival rate should theoretically reach 100%.

A second patient who received the same therapy is showing extremely encouraging results, according to data published in the New England Journal of Medicine. The research team believes prime editing could become a therapeutic platform for chronic granulomatous disease and other genetic conditions.

From genetic diseases present at birth to mutations acquired later like cancer, the full potential of prime editing remains unexplored. "We're no longer selling a dream, we're selling reality," Dr. Haddad said.